The overall objective of this project is to investigate the factors that define, determine, and predict the state of health and social well-being of elderly populations in the U.S. and Australia. Major domains of concern involve the effects of chronic degenerative diseases, including chronic non-life threatening conditions, functional impairment of older persons, as mediated by sociodemographic, environmental, lifestyle and health care assistant factors. Both within and between country differences and similarities in the U.S. and Australia will be investigated. The project involves the collaboration of the Duke University Center for Demographic Studies as the primary investigators and the Center for Ageing Studies, Flinders University of South Australia, as sub-Contractors. The cross-national analyses will draw upon relevant data from large, multi-dimensional longitudinal investigations conducted or under way in the U.S. (including the NHANES, NLTCS, Duke I and II longitudinal, the Yale University - New Haven EPESE and SOA-LSOA) and a new longitudinal, integrated study in Adelaide, Australia and entails multi-round household surveys, clinical examinations and linked records on a population-based, age and sex stratified sample of persons 60 years and older. Analyses of data will primarily utilize advanced multivariate history procedures (the grade of membership model) developed by the investigators at the Center for Demographic Studies for examining longitudinal multi-dimensional aging processes. The grade of membership model will permit cross study analyses to be conducted on relevant topics in the U.S. studies and cross national comparative investigations of the U.S. and Australian data.